The present invention relates to a sensor apparatus for detecting characteristics such as temperatures, pressures or the like, a configuration apparatus for making the setting for the sensor apparatus, and a read-out apparatus for reading out information from the sensor apparatus, and relates to a commodity management system that uses the sensor apparatus, configuration apparatus and read-out apparatus to conduct a management of commodities.
In a temperature control such as air conditioning, an air conditioning apparatus or the like is drive-controlled according to a decision result of whether or not detected temperature is within a tolerated temperature range, and a data-collecting apparatus is generally used for this decision. The data-collecting apparatus is constituted, for example, by a signal-processing circuit, having a thermosensitive device for detecting the temperature and an electronic circuit for converting an output of the thermosensitive device into an electric signal, and a controller connected to the signal-processing circuit for analyzing the output thereof.
In general, there are dispersions in the characteristics of the thermosensitive devices of the data-collecting apparatuses, and there is fear of the output (temperature detected by the thermosensitive device) of the electronic circuits not accurately indicating the actual temperature. Hence, calibration is done to decrease measurement errors caused by such dispersions.
For the calibration, a temperature measurement has been generally heretofore conducted by transmitting the output of the signal-processing circuit to the controller, after putting them in a constant temperature environment for a prescribed period of time in a state of being connected with each other through a cable or the like. Based on the relation of the signal-processing circuit output and the temperature acquired by conducting such temperature measurements in plural temperatures, the characteristics of the signal-processing circuit are calibrated on the controller side, and the calibrated result is stored in the controller. Before the shipment of the data-collecting apparatus, a tolerance value (tolerated temperature value for example) is set into the controller, which value prescribes the tolerated range for a parameter being detected by the sensor apparatus. In actual use of the data-collecting apparatus, the controller corrects the output of the signal-processing circuit (detected value) based on the calibration result, and performs a control in accordance with the result of comparison between the corrected detection value and the tolerance value.
With a conventional calibration method, therefore, it is necessary to constitute a data-collecting apparatus by use of a signal-processing circuit and a paired controller. This makes it impossible to constitute a data-collecting apparatus with a random signal-processing circuit and a random controller. Moreover, equipment such as a constant temperature bath becomes large-scale because calibration is done with the signal-processing circuit and the controller that are connected physically to each other.
Recently, a data-collecting apparatus has been proposed that includes signal-processing circuits each comprising a wireless communication function and configured to send the output of the sensor device thereof to the controller. The proposed apparatus has an advantage in being capable of detecting ambient temperature of any of a large number of commodities by having signal-processing circuits individually mounted thereon, but entails the following problems.
First of all, it is necessary to calibrate the characteristics of the individual signal-processing circuits, so as to decrease the measurement error caused by the dispersion (individual difference) of characteristics of the sensor apparatuses of the signal-processing circuits that causes the dispersion of outputs of the electronic circuits.
Secondly, since it is necessary to have the calibrated results of the individual signal-processing circuits stored in the controller beforehand, the individual signal-processing circuits and the controller are inseparable, which controller serves as a read-out apparatus for reading out information from the signal-processing circuits. A signal-processing circuit whose calibration result is not stored in the controller cannot be used with that controller. Thus, it is not possible to constitute a data-collecting apparatus with a random signal-processing circuit and a random controller.
Thirdly, the data-collecting apparatus is configured to process the outputs of the signal-processing circuits by means of a single controller, so that the controller is required to correct the individual circuit outputs on the basis of the calibration results for the respective signal-processing circuits stored therein. Therefore, the load on the controller becomes enormous with the increase in the number of signal-processing circuits, and there is a limit to the number of signal-processing circuits a single controller can handle.